The present invention is directed to a valve assembly with a disk-like valve body for discharging a fluid from a container, such as a flexible collapsible container, while preventing back flow into the container, particularly of contaminants. The valve assembly is formed of a valve body with an inlet at one end and a passageway extending through the valve body from the inlet. The valve body has an outlet spaced from the inlet with a passageway within the valve body connected to the outlet. An elastomeric sheath tightly encloses the outer surface of the valve body. The elastomeric sheath can expand outwardly permitting flow from the inlet passageway into the space between the inside surface of the sheath and the outside surface valve body. The fluid in the space between the sheath and the valve body then flows through the outlet passageway to the outlet. The elastomeric sheath prevents any back flow from the outlet passageway to the inlet passageway after the fluid is dispensed.
In dispensing sterile fluids from a container, especially when the container has an extended use lifetime, it is important to prevent any back flow of contaminants into the container during and following the dispensing operation. Contamination from the ambient atmosphere may include micro-organisms, atmospheric gases, moisture, dust and the like. If a sterile fluid is contaminated it can affect its quality, potency and even the safety of the fluid.
If a container of sterile fluid has a one-time use and is not intended to be dispensed over an extended period of time, the problem of contaminants entering the containers usually does not exist.
Sterile fluid may involve a variety of products, such as drugs, beverages, cosmetics and the like. The fluid may be a liquid, lotion, cream, gel, powder, gas or the like.
The present invention is an improvement on the valve assembly disclosed in U.S. Pat. No. 4,846,810 hereinafter referred to as the ReSeal Valve. In the ReSeal Valve an axially elongated valve body was used enclosed within an elastomeric sheath. While the ReSeal Valve is effective in maintaining the sterility of a fluid within a container, the formation of the flow passages through the valve body can increase its cost. Further, the axial elongation of the valve may interfere with its utility.